Automation of Large Parametric Flow Assurance Analyses in the Cloud

2021 ◽  
Author(s):  
Rex Sinclair Hubbard ◽  
Leon Geoffrey Staaden ◽  
Derek John Scales ◽  
Andrew Chin Foong Tran
Keyword(s):  
Full Range ◽  
Operating Conditions ◽  
Flow Assurance ◽  
Fluid Temperature ◽  
Reference Case ◽  
Worst Case ◽  
Analysis Process ◽  
Bulk Data ◽  
High Level ◽  
Rate Criterion

Abstract The objective of this study was to determine the highest flowrate through a client's existing flowline without top-of-line condensation rates exceeding a critical value of 0.25 g/m2.s. Automation of the workflow allowed a large combination of operating conditions to be analysed within a shorter timeframe than a traditional flow assurance analysis process. A multiparameter case matrix was developed to analyse the full range of process and environmental variables. A proprietary multiphase flow assurance software in the cloud was used to develop a reference case model. Then a software script was developed to read in the reference case model's code and produce input files for 1,080 cases. All cases were run within 30 minutes in the cloud. Another software script then extracted key data from the 1,080 output files into a single Excel spreadsheet to enable data visualisation and identification of a simple and effective flow rate criterion to limit condensation rates. Automation of the workflow allowed all combinations of variables to be analysed within a shorter timeframe compared to the traditional flow assurance analysis process, which usually analyses a somewhat limited number of suspected worst-case scenarios selected based on engineering judgement. The bulk data resulting from the automated workflow enabled a single integrity limit criterion to be applied with a high level of confidence, namely the fluid temperature measured at a subsea corrosion probe. This simplified integrity limit allows the operators to easily maximise production for any combination of process and environmental conditions, whilst maintaining confidence that they are not exceeding the critical condensation rate.

The behaviour of heavily loaded line contacts with transverse roughness

1999 ◽  
Vol 213 (4) ◽  
pp. 309-320 ◽  
Author(s):  
C. J. Hooke
Keyword(s):  
Surface Roughness ◽  
Full Range ◽  
Numerical Results ◽  
Operating Conditions ◽  
Entrainment Velocity ◽  
Original Surface ◽  
Line Contacts ◽  
Transverse Roughness ◽  
Inlet Length

In heavily loaded, piezoviscous contacts the surface roughness tends to be flattened inside the conjunction by any relative sliding of the surfaces. However, before it is flattened, the roughness affects the inlet to the contact, producing clearance variations there. These variations are then convected through the contact, at the entrainment velocity, producing a clearance distribution that differs from the original surface. The present paper explores this behaviour and establishes how the amplitude of the convected clearance varies with wavelength and operating conditions. It is shown that the primary influence is the ratio of the wavelength to the inlet length of the conjunction. Where this ratio is large, the roughness is smoothed and there is little variation in clearance under the conjunction. Where the ratio is small, significant variations in clearance may occur but the precise amplitude and phasing depend on the ratio of slide to roll velocities and on the value of a piezoviscous parameter, c. The numerical results agree closely with existing solutions but extend these to cover the full range of operating conditions.

Efficient Analysis of a Catenary Riser

2006 ◽  
Author(s):  
Elizabeth Passano ◽  
Carl M. Larsen
Keyword(s):  
Operating Conditions ◽  
Stochastic Simulations ◽  
Worst Case ◽  
Nonlinear Structure ◽  
Tension Response ◽  
Extreme Response ◽  
Analysis Strategies ◽  
Low Tension ◽  
Term Response

The paper deals with the challenge of predicting the extreme response of catenary risers, a topic of both industry and academic interest. Large heave motions introduced at the upper end of a catenary riser can lead to compression and large bending moments in the region immediately above the touch down area. In the worst case, dynamic beam buckling may occur. The focus of the paper will be on understanding the riser behaviour in extreme, low-tension response and in establishing suitable analysis strategies to predict the extreme response. Results from long nonlinear stochastic simulations of many sea states with varying environmental and operating conditions may be combined to describe the long-term response of a nonlinear structure such as a catenary riser. However, this theoretically straight-forward approach is very demanding computationally and ways to limit the extent of nonlinear stochastic simulations are therefore sought. The usefulness of simpler methods such as regular wave analysis to improve understanding of the physical behaviour and to aid in concentrating the nonlinear simulations to where they are most useful, will be demonstrated.

Proving the Labeled Interval Calculus for Inferences on Catalogs

1990 ◽  
Author(s):  
Walid Habib ◽  
Allen C. Ward
Keyword(s):  
Mechanical Design ◽  
Formal System ◽  
Constraint Propagation ◽  
Operating Conditions ◽  
Manufacturing Processes ◽  
Entire System ◽  
High Level Language ◽  
Design Problems ◽  
High Level ◽  
Interval Constraint

Abstract The “labeled interval calculus” is a formal system that performs quantitative inferences about sets of artifacts under sets of operating conditions. It refines and extends the idea of interval constraint propagation, and has been used as the basis of a program called a “mechanical design compiler,” which provides the user with a “high level language” in which design problems for systems to be built of cataloged components can be quickly and easily formulated. The compiler then selects optimal combinations of catalog numbers. Previous work has tested the calculus empirically, but only parts of the calculus have been proven mathematically. This paper presents a new version of the calculus and shows how to extend the earlier proofs to prove the entire system. It formalizes the effects of toleranced manufacturing processes through the concept of a “selectable subset” of the artifacts under consideration. It demonstrates the utility of distinguishing between statements which are true for all artifacts under consideration, and statements which are merely true for some artifact in each selectable subset.

Transport Characteristics of a Multi-Species Slurry in a Horizontal Pipeline

2001 ◽  
Author(s):  
P. V. Skudarnov ◽  
H. J. Kang ◽  
C. X. Lin ◽  
M. A. Ebadian ◽  
P. W. Gibbons ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Deposition Velocity ◽  
Single Species ◽  
Operating Conditions ◽  
High Level Waste ◽  
Slurry Flow ◽  
Flow Loop ◽  
Waste Transfer ◽  
High Level ◽  
Slurry Transport

Abstract In the course of the U.S. Department of Energy’s (DOE) tank waste retrieval, immobilization, and disposal activities, high-level waste transfer lines have the potential to become plugged. In response to DOE’s needs, Florida International University’s Hemispheric Center for Environmental Technology (FIU-HCET) is studying the mechanism and behavior of pipeline plugging to determine the pipeline operating conditions for safe slurry transport. Transport behavior of multi-species slurry has been studied in a 1-in O.D. pipeline flow loop. The slurry was a five-species mixture of Fe2O3, Al2O3, MnO2, Ni2O3, and SiO2, which simulated actual waste at the Savannah River DOE site. The relationship between the pressure drop in the straight horizontal sections of the flow loop and the mean slurry flow velocity was determined for two solids volume concentrations of 5.2 and 7.8%. Critical deposition velocity was measured from visual observations. An existing empirical model that predicts the pressure gradient for a single-species slurry flow in a horizontal pipeline was used to describe the pressure drop data.

Muscle function during jumping in frogs. I. Sarcomere length change, EMG pattern, and jumping performance

1996 ◽  
Vol 271 (2) ◽  
pp. C563-C570 ◽  
Author(s):  
G. J. Lutz ◽  
L. C. Rome
Keyword(s):  
Mechanical Properties ◽  
Muscle Function ◽  
Length Change ◽  
Operating Conditions ◽  
Mechanical Power ◽  
Shortening Velocity ◽  
Jumping Performance ◽  
Angular Velocities ◽  
High Level

We determined the influence of temperature on muscle function during jumping to better understand how the frog muscular system is designed to generate a high level of mechanical power. Maximal jumping performance and the in vivo operating conditions of the semimembranosus muscle (SM), a hip extensor, were measured and related to the mechanical properties of the isolated SM in the accompanying paper [Muscle function during jumping in frogs. II. Mechanical properties of muscle: implication for system design. Am. J. Physiol. 271 (Cell Physiol. 40): C571-C578, 1996]. Reducing temperature from 25 to 15 degrees C caused a 1.75-fold decline in peak mechanical power generation and a proportional decline in aerial jump distance. The hip and knee joint excursions were nearly the same at both temperatures. Accordingly, sarcomeres shortened over the same range (2.4 to 1.9 microns) at both temperatures, corresponding to myofilament overlap at least 90% of maximal. At the low temperature, however, movements were made more slowly. Angular velocities were 1.2- to 1.4-fold lower, and ground contact time was increased by 1.33-fold at 15 degrees C. Average shortening velocity of the SM was only 1.2-fold lower at 15 degrees C than at 25 degrees C. The low Q10 of velocity is in agreement with that predicted for muscles shortening against an inertial load.

Optimal State-Space Control of a Gas Turbine Engine

1992 ◽  
Vol 114 (4) ◽  
pp. 763-767 ◽  
Author(s):  
J. W. Watts ◽  
T. E. Dwan ◽  
C. G. Brockus
Keyword(s):  
State Space ◽  
Gas Turbine ◽  
State Space Model ◽  
Gas Turbine Engine ◽  
The State ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Analog Control ◽  
Linear State ◽  
High Level

An analog fuel control for a gas turbine engine was compared with several state-space derived fuel controls. A single-spool, simple cycle gas turbine engine was modeled using ACSL (high level simulation language based on FORTRAN). The model included an analog fuel control representative of existing commercial fuel controls. The ACSL model was stripped of nonessential states to produce an eight-state linear state-space model of the engine. The A, B, and C matrices, derived from rated operating conditions, were used to obtain feedback control gains by the following methods: (1) state feedback; (2) LQR theory; (3) Bellman method; and (4) polygonal search. An off-load transient followed by an on-load transient was run for each of these fuel controls. The transient curves obtained were used to compare the state-space fuel controls with the analog fuel control. The state-space fuel controls did better than the analog control.

scholarly journals Experimental and Theoretical Analysis of a Linear Focus CPV/T System for Cogeneration Purposes

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2960 ◽  
Author(s):  
Carlo Renno
Keyword(s):  
Focal Length ◽  
Concentration Field ◽  
Operating Conditions ◽  
Working Fluid ◽  
Fluid Temperature ◽  
Atmospheric Conditions ◽  
High Concentration ◽  
Environment Temperature ◽  
Temperature Levels ◽  
T System

The knowledge of the actual energy performances of a concentrating photovoltaic and thermal (CPV/T) system with a linear focus optics, allows to evaluate the possibility of adopting this type of system for cogeneration purposes. Hence, the main aim of this paper is the design, realization, setting and modeling of a linear focus CPV/T system in the high concentration field. An experimental linear focus CPV/T plant was created in order to determine its electrical and thermal performance under different working conditions in terms of environment temperature, sunny and cloudy conditions, focal length, etc. Moreover, a theoretical model of the linear focus CPV/T system was also studied. This model evaluates the temperatures of the working fluid that flows in the cooling circuit of the CPV/T system under several operating conditions. The temperatures of the triple junction (TJ) cells, experimentally evaluated referring to different solar radiation and atmospheric conditions, were considered as the input data for the model. The values of the fluid temperature, theoretically and experimentally determined, were thus compared with good agreement. The electrical production of the CPV/T system depends generally on the TJ cell characteristics and the concentration factor, while the thermal production is above all linked to the system configuration and the direct normal irradiance (DNI) values. Hence, in this paper the electric power obtained by the linear-focus CPV/T system was evaluated referring to the cogeneration applications, and it was verified if the TJ cell and the cooling fluid reach adequate temperature levels in this type of system, in order to match the electrical and the thermal loads of a user.

scholarly journals Selection of efficient ships according to the criterion of marginal price at the feasibility study

2021 ◽  
pp. 172-181
Author(s):  
Oksana Y. Vasileva ◽  
Marina V. Nikulina Nikulina ◽  
Juri I. Platov Platov
Keyword(s):  
Fuel Consumption ◽  
Feasibility Study ◽  
Information Technologies ◽  
Optimization Methods ◽  
Relevant Information ◽  
Operating Conditions ◽  
Initial Stage ◽  
Level Of Use ◽  
High Level ◽  
Selection Of

The article deals with the problem of selecting efficient ships by the feasibility study in which brake power, main dimensions, payload, speed and fuel consumption are determined. The necessity of using the proposed selection at the initial stage of the ship's design is justified; the problems that arise at the present time are denoted. The purpose of the article is to propose a criterion for the selection of efficient vessels, "tied" to the operating conditions, based on the marginal cost of the ship. A method for its determination is presented. At the same time, annual revenues and operating costs should be determined by modern methods of business planning for the operation of the fleet. When searching for the parameters of the ship, the optimal fuel consumption is determined. The rest of the costs can be found according to the coefficients "tied" to the fuel consumption and calculated on the basis of existing prototypes. The results of calculations by the proposed method are shown; its merits and opportunities for improvement are noted with the availability of relevant information. The conclusion is made about the convenience and applicability of the proposed option for selecting efficient ship for the feasibility study based on optimization methods for determining the parameters of vessels under conditions of a high level of use of information technologies.

Optimization in Design of High-g Accelerometers

2007 ◽  
Author(s):  
Jun Liu ◽  
Xiaojin Qi ◽  
Yunbo Shi ◽  
Fai Ma
Keyword(s):  
Full Range ◽  
Operating Conditions ◽  
Fabrication Process ◽  
Optimized Design ◽  
Bridge Structure ◽  
Mass Center ◽  
Etch Stop ◽  
Impact Experiments

Under the operating conditions of high collision and strong vibration, a new high-g piezoresistive accelerometer (with a full range of 150000g) is designed. This design consists of 4-beams and 1-tower. This structure possesses superior anti-shock ability. In optimizing this piezoresistive bridge structure, a tower is etched directly from the back of the mass in KOH by using the (111) plane etch-stop technique. Since the distances between the mass center of the tower and the mass centers of the beams are shortened, anti-shock ability in transverse directions is improved. In addition, the fabrication process is relatively straightforward. Finally, it is found by impact experiments that the linearity of the optimized design lies within 9% for measurements in the range of 0–150000g.

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